Improvement in boat-detaching apparatus



wweeaaaww seA JOHN ATWOOD, JR.,'ANDVTHOMAS M. HATCH, OF PROVINCETOWN,

MASSACHUSETTS.

Lene/rs Patent No. 86,490, lated Fama/ry 2, 1869.

IMPROVEMENT IN BOAT-DETACHIN G- APPARATUS.

Be it known that we, JOHN Arwoon, JR., and THOMAS M. HATCH, both of Provincetown, in tbe county of Barnstable, and State of Massachusetts, have invented a new and Aimproved Self-Detachiug Davit, or Boat-Tackle, of which the following isa full, clear, and exact description, reference being had to the accompanying drawings, making a part of this specication, in which- Figure 1 is a side elevation of a tackle-block embodying our invention. i r

Figure 2 is a transverse vertical elevation in a plane parallel to the axis of the pulleys or sheaves; and

Figure 3v is a side elevation of a block, one cheek having been removed, showing the interior mechanism of one arrangement of our invention.

The object of our invention is to furnish a ready and elicient means of instantly detaehing a boat, when low-V ered from the davits of a vessel of any description,

vWhether at rest o1` in motion, in a smooth or rough sea, the instant such boat touches the water, or floats.

Further, our general purpose is to furnish a tackleblock, which will release itself when at a point inac cessible to workmen, or which, by releasing itself after the safe deposition of the load attached, of what naf ture soever, will econornize time.

`The invention consists in such a` combination of the hook and block, that, after the withdrawal of a retaining bolt, or pin, the hook of the block is instantly, when the strain upon the block is relieved, thrown from its usual position, setting free the rope or pinA attached to it.

Our invention may be'applied to any tackle attached to a mass, which i is desired to deposit in an inaccessible position, or a the bottom of a river or harbor.

Time would be much economized by its employment as a part of the tackle of all lifts and derricks, for the immediate detachment of the load from the dei-rick, or lift, when it is laid in the proper place, would greatly increase the eciency of such deriick, enabling it to perform much more work in a given time.-

Our invention is especially applicable for the releasing of ships boats from theda-vits under all circumstances. Nautical exigencies -demand that no time shall be lost, and the swampiug and staving in of boats,

resulting from their detachment not having been ei`- fected at the rightmoment, is often attended with loss of life.

Referring to the drawingsa, is the frame, or shell ofthe block. It contains two chambers, in which the sheaves e e turn freely about a pin, f, which passes entirely through `the block transversely, andis securedV at the ends, as in the block at present employed. A ring, for attaching the block to the rope, isfiXed to itsb upper end.

A narrow, deep, vertical slot or chamber penetrates the middle ofthe block, from its front almost to the back, as shown in iig. 3. This chamber allows the hook c to be turned about its axis j'.

The hook c has a long straight shank, through the upper part of which the axis j' passes. This hook c is so shaped that, when turned about the axis f, a rope or ring would be detached freely, and without hitching, from the hook.

Vith the hook c, a spring of metal, or .other elastic material, is so combined that, when the shank of the hook c is in a vertical position, the spring is compressed 4or extended.

'in the usual manner.

sents an elastic rubber cord,` or strap, one end being attached to the hook c, and the other to the upper part of the chamber, in any suitable manner.

The hook c can readily be returned to its usual place, the bolt y reinserted, and the block again be ready for use.

The tackle-block, constructed as abovedescribed, is

in no respect necessarily weaker than those of the or-l dinary construction.

The `detachment of the hook of blocks now in u se requires often considerable time and theexpenditure of a good deal of strength.

In certain cases the bolt g may be dispensed with altogether, but it is well to retain it, so that the block may be employed when self-detachment is not desired.

What we claim as our invention, and desire'to secure by Letters Patent, is-

l. The movable hook c, in combination with the block, constructed and operated as described.

2. The block a., in combination with the hook c and` a spring, substantially as and for the purpose set forth. In testimony whereof, we have signed our names to this specification, in the presence of two subscribing JOHN ATWOOD, JR. THOMAS M. HATCH.

witnesses.

Witnesses:

B. F. HUToHmsoN, BENJ. T. OROCKER. 

